Transmission of Compressed Data Stream with Compensation Values

ABSTRACT

In a data transmission system such as a television service provider system, compensation value data corresponding to information lost during lossy compression of program content (which may or may not already be compressed prior to the lossy compression) may be sent to a customer along with the lossy-compressed content. At the customer end, the compensation value data may be used during decompression to provide higher quality content to the customer than would otherwise be experienced without access to the compensation values.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 12/644,377, filed Dec. 22, 2009, entitled “Transmission ofCompressed Data Stream with Compensation Values,” hereby incorporated byreference as to its entirety.

BACKGROUND

Television service providers typically multiplex a large number ofchannels onto a single transport medium. The content for these channelsis usually compressed into one or more Moving Picture Experts Group(MPEG) standard transport streams, with each channel being representedby a different program identifier (PID) contained in each data packet.Each transport stream is, in turn, modulated onto a respective carrierwave within a dedicated region of bandwidth around that carrier wave.Each region of bandwidth is sometimes referred to as a “QAM,” which alsostands for “quadrature amplitude modulation,” because that is a typicalcarrier modulation technique used. In fact, the term QAM is variouslyused to refer to the carrier modulation technique, the region ofbandwidth, and even equipment used to perform the modulation orotherwise process the modulated transport stream.

Each QAM bandwidth region typically has a fixed maximum bandwidthcapacity and contains a subset group of the channels. For instance, aparticular QAM bandwidth region may contain two or more high-definitionchannels per QAM bandwidth region, or ten to twenty standard definitionchannels. Regardless of how the channels, or PIDs, are divided amongstthe QAM bandwidth regions, the total bandwidth of the channels carriedon a QAM bandwidth region is not supposed to exceed the total fixedcapacity of that QAM bandwidth region. However, the total bandwidth of agroup of channels is difficult to determine, because the actualbandwidth needed by each channel can vary widely and unpredictably overtime. Factors that affect the variability in bandwidth needed by achannel include, for instance, the amount of motion in a video scene orthe number of quick cuts between scenes.

Therefore, while television service providers would like to maximize thenumber of channels on each QAM bandwidth region, they are limitedsomewhat by unpredictable variations in actual bandwidth used by thechannels. If the actual bandwidth exceeds the QAM bandwidth regioncapacity, then the quality of the content may temporarily drop for allMPEG streams contained within the same QAM bandwidth region, resultingin artifacts such as blocking and freezing of video and distortion ofaudio. The provider can put fewer channels on each QAM bandwidth regionto reduce the probability of exceeding QAM bandwidth region capacity.However, this is not ideal because a portion of bandwidth in that regionwill go unused most of the time. To deal with this problem, manyproviders implement an MPEG groomer, which further compresses thecontent for each channel on a QAM bandwidth region at times when thetotal bandwidth needed by the channels on that QAM bandwidth regionwould otherwise exceed the capacity of that bandwidth region. Thisadditional compression (sometimes called “recompression”) is typicallylossy, meaning that information is irreversibly removed from thetransmitted data so that the data may be smaller. Therefore, suchrecompression causes an inevitable drop in content quality as receivedby the customer/television viewer. While the recompression quality dropis expected to be smaller and more controllable than the quality dropthat would occur by simply letting the actual bandwidth exceed thecapacity of the QAM bandwidth region, such a quality drop is stillundesirable.

SUMMARY

Techniques are discussed that may reduce or even eliminate the qualitydrop experienced by the viewer when lossy compression (e.g., initialcompression and/or subsequent recompression) is performed. In general,data representing compensation values corresponding to the informationlost during compression may be sent to the customer along with thecompressed content. At the customer end, the compensation values may beused during decompression to provide higher quality content to thecustomer than would otherwise be experienced without access to thecompensation values. By having access to the compensation values, thecustomer receiver equipment may therefore partially or fully reverse thecompression performed by the service provider's MPEG groomer.

To avoid utilizing bandwidth in a QAM bandwidth region in which thecontent is already being compressed (referred to herein as a “contentQAM”), the compensation values may be transmitted utilizing bandwidthoutside that content QAM. For example, the compensation values may beprovided on a QAM bandwidth region (referred to herein as a“compensation QAM”) different from the content QAM on which theassociated compressed content is transmitted. Thus, the informationpreviously lost to compression may still be received by the customerwithout requiring any additional bandwidth in the content QAM. Inaddition, multiple content QAMs may share the same compensation QAMand/or utilize more than one compensation QAM.

Thus, for example, some aspects are directed to a method, comprising:compressing data to generate compressed data; determining compensationvalue data representing information lost during said compression;transmitting at least a portion of the compressed data in a firstfrequency band; and transmitting the compensation value data in a secondfrequency band different from the first frequency band.

Further illustrative aspects are directed to a system, comprising acompressor and a transmitter. The compressor may be configured tocompress data to generate compressed data, and determine compensationvalue data representing information lost during compression. Thetransmitter may be configured to transmit the compressed data in a firstfrequency band, and transmit the compensation value data in a secondfrequency band different from the first frequency band.

Still further illustrative aspects are directed to a method, comprisingreceiving a first transmission in a first frequency band, the firsttransmission representing compressed data; receiving a secondtransmission in a second frequency band different from the firstfrequency band, the second transmission representing compensation valuedata; decompressing at least a portion of the compressed data using atleast some of the compensation value data to generate decompressed data;and displaying the least a portion of the decompressed data as video ona display device.

Yet further illustrative aspects are directed to an apparatus,comprising a receiver and a decompressor. The receiver may be configuredto receive a first transmission in a first frequency band, the firsttransmission representing compressed data, and receive a secondtransmission in a second frequency band different from the firstfrequency band, the second transmission representing compensationvalues. The decompressor may be configured to decompress at least aportion of the compressed data using at least some of the compensationvalues to generate decompressed data.

These and other aspects of the disclosure will be apparent uponconsideration of the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present disclosure and thepotential advantages of various aspects described herein may be acquiredby referring to the following description in consideration of theaccompanying drawings, in which like reference numbers indicate likefeatures, and wherein:

FIG. 1 is a functional block diagram of an illustrative system fortransferring compressed data to one or more customers;

FIG. 2 is a functional block diagram of an illustrative computer thatmay be used to implement one or more elements of the system of FIG. 1;

FIG. 3 graphically shows illustrative QAM bandwidth regions in which thecompressed data may be transferred;

FIG. 4 is a graph showing illustrative utilized bandwidth over timewithin one of the bandwidth regions of FIG. 3;

FIG. 5 is a flowchart of an illustrative process that may be performedby the system of FIG. 1 to transfer the compressed data to the one ormore customers;

FIG. 6 is a graph showing illustrative utilized bandwidth over timewithin one of the frequency bands of FIG. 3 used as a compensationfrequency band (e.g., compensation QAM); and

FIG. 7 is a flowchart of an illustrative process that may be performedby one or more of the clients of FIG. 1 to decompress the receivedcompressed data utilizing compensation values.

DETAILED DESCRIPTION

FIG. 1 is a functional block diagram of an illustrative system (such asa cable, fiber optic, satellite, or hybrid television program providersystem) for transferring compressed data to one or more viewers or otherclients. The system in this example includes a content/data source 101,a compressor 102, an edge QAM 103, a network 104, a first clientrepresented by customer premises equipment (CPE) 105 and a second clientrepresented by CPE 106. Each of CPE 105, 106 may include or be coupledto a display device 107, 108, such as a television display or computerdisplay. Although each functional block 101-106 is shown as a singleelement in FIG. 1, it is to be understood that any of the functionalblocks 101-106 may be implemented as one or more physical units. Each ofthe functional blocks 101-106 will now be discussed in turn.

Content/data source 101 may generate or otherwise provide data to becompressed by the system. The data may represent, for example, audioand/or video content (such as a television show or a movie) that may ormay not already be compressed such as by MPEG compression. However, thedata may be any arbitrary type of data that is desired to be transferredto CPE 105 and/or CPE 106.

Compressor 102 compresses the data received from content/data source 101using any type of compression desired. For example, compressor 102 maycompress the data into one or more transport streams, such as MPEGtransport streams. Compressor 102 may be or otherwise include an MPEGgroomer. Where the data from content/data source 101 is alreadycompressed, the compression performed by compressor 102 may berecompression. In general, the terms “compression,” “compress,” or“compressed” as used herein refers to both initial compression and anysubsequent recompression, unless otherwise specified.

Compressor 102 may determine whether compression is needed, and/or theamount and/or type of compression to be used, based on the bandwidth ofthe data received from content/data source 101. The determination maydepend upon whether the content data destined for one or more contentQAMs will fit within those content QAMs. In other words, for eachcontent QAM in which the associated content data bandwidth is determinedto exceed the bandwidth of that content QAM, compressor 102 may compress(which includes initial compression or recompression after initialcompression) the content data so as to fit within that content QAM.Compressor 102 may also generate compensation values based on thatcompression. Data representing the compressed content data and thecompensation values are then fed to edge QAM 103 for distribution tocustomers. Compressor 102 may further compress the compensation valuedata if desired.

Edge QAM 103 in turn modulates the received compressed data andcompensation value data, modulates the compressed data and/orcompensation value data into one or more content QAMs and/orcompensation QAMs, and forwards the content and/or compensation QAMs toCPE 105 and 106 (and/or other CPEs) via network 104. Edge QAM 103 mayinclude a transmitter as network input/output interface 204 (FIG. 2)that is capable of simultaneously transmitting to network 104 thecontent QAM(s) and/or the compensation QAM(s).

Network 104 may be any type of network or combination of networks, suchas but not limited to the Internet, a dedicated cable, fiber optic,satellite, or hybrid television distribution network, a wirelesscellular network, and/or a local area network. Network 104 may beconfigured so as to have sufficient capacity to provide the modulatedcontent and/or compensation QAMs in near real time.

CPE 105 and 106 may each be or otherwise include any type of device orsystem for receiving, processing, decompressing, and rendering thecontent data on the content QAMs. CPE 105 and 106 may further be capableof receiving and utilizing the compensation values during decompression.In the present example, each of CPE 105 and 106 includes a decompressor109, 110, and two tuners arbitrarily named Tuner A and Tuner B. Thesetuners may be physically implemented separately (e.g., two separate setsof tuner circuitry) and/or may be physically implemented as a singletuner with multiple simultaneous tuning capability (e.g., a singlephysical tuner implementing two logical tuners). In either case, CPE 105and 106 may each be configured to be capable of simultaneously receivingand tuning to more than one channel in one or more content QAMs and/orcompensation QAMs. Thus, for example, CPE 105 and 106 may each becapable of tuning not only to a particular content PID in a particularcontent QAM, but also simultaneously to a particular PID in acompensation QAM containing the compensation value data. Manyconventional CPE devices already contain multi-tuning capability, suchas set top boxes and television sets having picture-in-picture (PiP)functionality. In such a case, Tuner A may be the standard tuner andTuner B may be the PiP tuner, or vice-versa. Tuners A and B may alsoinclude receivers for receiving all data from network 104. Decompressors109, 110 may be implemented as dedicated hardware decompressors, and/oras software decompressors. For instance, decompressors 109, 110 may beimplemented by functions performed by processor 201 (FIG. 2).

All of functional blocks 101, 102, 103, 105, and 106 each may beimplemented as, or otherwise include, one or more computers. The term“computer” as referred to herein broadly refers to any electronic,electro-optical, and/or mechanical device, or system of multiple suchdevices, that is able to process and manipulate analog and/or digitalinformation, such as in the form of data. Non-limiting examples of acomputer include one or more personal computers (e.g., desktop orlaptop), servers, cellular phones, personal digital assistants (PDAs),television set top boxes, and/or a system of these in any combination orsubcombination. In addition, a given computer may be physically locatedcompletely in one location or may be distributed amongst a plurality oflocations (i.e., may implement distributive computing). A computer maybe or include a general-purpose computer programmable to implement awide variety of functions, and/or a dedicated computer that isconfigured to perform only certain limited functions.

An example functional-block representation of a computer 200 is shown inFIG. 2, from which any of blocks 101, 102, 103, 105, and 106 may beimplemented. Computer 200 may include hardware that may execute softwareand/or be configured in hardware to perform specific functions. Thesoftware may be stored on a computer-readable medium 202 in the form ofcomputer-readable instructions. Computer 200 may read thosecomputer-readable instructions, and in response perform various steps asdefined by those computer-readable instructions. Thus, any functionsattributed to blocks 101, 102, 103, 105, and 106 as described herein maybe implemented, for example, by reading and executing suchcomputer-readable instructions for performing those functions, and/or byany hardware subsystem (e.g., a processor 201) from which computer 200is composed.

The term “computer-readable medium” as used herein includes not only asingle physical medium or single type of medium, but also a combinationof one or more physical media and/or types of media. Examples of acomputer-readable medium include, but are not limited to, one or morememory chips, hard drives, optical discs (such as CDs or DVDs), magneticdiscs, flash drives, and magnetic tape drives.

Such a computer-readable medium 202 may store computer-readableinstructions (e.g., software) and/or computer-readable data (e.g.,information that may or may not be executable). In the present example,computer-readable medium 202 (such as memory) may storecomputer-executable instructions and/or data used by any of blocks 101,102, 103, 105, 106. Alternatively or additionally, such acomputer-readable medium 202 storing the data and/or software may bephysically separate from, yet accessible by, blocks 101, 102, 103, 105,106.

Computer 200 also includes a user input/output interface 203 forreceiving input from a user (e.g., via a keyboard, mouse, and/or remotecontrol) and providing output to the user (e.g., via display device 107or 108, an audio speaker, and/or a printer). Computer 200 furtherincludes a network input/output interface 204 for communicating with anetwork such as network 104, and/or for communicating with externaldevices directly. Thus, any communication between blocks 101, 102, 103,105, and 106 and users, network 104, and each other may be attributed tocommunication via user input/output interface 203 and/or networkinput/output interface 104 of those respective blocks.

FIG. 3 graphically shows illustrative QAM bandwidth regions QAM-1,QAM-2, QAM-3, and QAM-4, in which the compressed data may be transferredover network 104. The QAM bandwidth regions may be content QAMs and/orcompensation QAMs. For example, QAM-1, QAM-2, and QAM-3 may each be acontent QAM containing multiple content channels, and QAM-4 may be acompensation QAM. While QAM-1, QAM-2, QAM-3, and QAM-4 are eachillustratively shown as a single continuous frequency band, one or moreof QAM-1, QAM-2, QAM-3, and QAM-4 may each be composed of multiplediscontinuous frequency bands. Also, while a compensation QAM such asQAM-4 may be a dedicated compensation QAM, the compensation value datatherein may share bandwidth with other data, such as in the same QAMthat transfers data, such as DOCSIS (Data Over Cable Service InterfaceSpecification) data. Also, while QAM-1, QAM-2, QAM-3, and QAM-4 are eachillustratively shown as frequency bands that do not overlap each otherin frequency, it is possible that one or more of these frequency bandsmay overlap in frequency.

FIG. 4 is a graph showing illustrative utilized bandwidth over timewithin one of the bandwidth regions of FIG. 3, such as QAM-1. In thisexample, content QAM-1 includes twelve channels (arbitrarily numbered1-12), and has a maximum fixed bandwidth capacity of 38.81 Mbit/sec(which is the standard maximum capacity for a 256-QAM modulated 6 MHzwide QAM bandwidth region). While much of the time the total utilizedbandwidth is less than the maximum bandwidth capacity, in a fewinstances (e.g., at about time=2, time=4, and time=10) the totalutilized bandwidth for channels 1-12 equals or approaches 38.81Mbit/sec. Thus, at and/or around those identified times, compressor 102may identify this situation, and in response compress the data for oneor more of channels 1-12 such that the total bandwidth of channels 1-12is equal to or less than 38.81 Mbit/sec, as would be accomplished by aconventional MPEG groomer. In addition, compressor 102 would generatecompensation values associated with the compression. Of course, othermaximum bandwidths may be used, depending upon the configuration of theQAM bandwidth regions. For example, a QAM bandwidth region using 64-QAMmodulation would normally have a maximum bandwidth capacity of 26.97Mbit/sec.

FIG. 5 is a flowchart of an illustrative process that may be performedby the system of FIG. 1 to transfer the compressed data to the one ormore customers. In step 501, content data provided by content/datasource 101 may be compressed (if not already compressed) by compressor102 for modulation into one or more content QAMs. Compressor 102 mayknow the maximum allowable bandwidth of each content QAM, and may checkto ensure that the total compressed bandwidth of the content for eachQAM does not exceed the maximum allowable bandwidth (or does not exceedsome other threshold bandwidth less than the maximum allowablebandwidth). In other words, for each set of channels destined for agiven content QAM, compressor 102 may determine whether the content forthat set of channels will fit within the associated content QAM (step502). If, for a given content QAM, the content will fit (such as occursat times=5 through 9 in FIG. 4), then in step 505 the content as-is isformatted and modulated by edge QAM 103 into the content QAM, and instep 506 the content QAM is sent into network 104 for broadcasting,multicasting, unicasting, or other type of transmission to CPE 105and/or 106. Because multiple content QAMs are typically sentsimultaneously with each other, the above process may be performed forall of those content QAMs.

If, however, the content for the set of channels is determined not tofit (such as might occur at time=2 in FIG. 4), then compressor 102 maycompress, or further compress, the data for that content such that itwill fit (step 503). For example, compressor 102 may sufficientlycompress the content of QAM-1 such that its bandwidth is no greater than40 Mbit/sec. The type and amount of compression may be altered as neededto ensure the utilized bandwidth is maintained within the establishedlimit. As discussed previously, in many cases such compression mayinvolve lossy compression because non-lossy compression would beinsufficient to reduce the bandwidth below the established limit. Inthat case, compressor 102 may generate one or more compensation valuesin step 504 and forward those compensation values as data along with thecompressed content to edge QAM 103. In turn, in steps 505 and 506, edgeQAM 103 processes the compressed content as data packets, eachidentifying the channel PID, into a content QAM, and processes thecompensation values as data packets, each identifying a compensationvalue PID, into a compensation QAM that utilizes bandwidth that may bedifferent from the content QAM. It is noted that such lossy compressionmay be performed in addition to any earlier lossy or non-lossycompression already performed on the content. Thus, the determination ofwhether the content bandwidth exceeds the content QAM maximum bandwidthmay be based on the bandwidth of the initially compressed content asreceived by compressor 102.

The compensation values may be values that identify the information lostduring the lossy compression. For example, where the lossy compressionloses higher resolution information (e.g., highly detailed imagefeatures), the compensation values may identify that higher resolutioninformation. Any one or more features of the video and/or audio signalmay be lowered in resolution in this lossy compression process. Forexample, the number of available colors may be reduced and/or the numberof pixels in each video image frame may be reduced. Another way tocompress the video may be to alter the compression quantization matrixto eliminate higher frequency components from the image.

In another example, encoding similar to JPEG 2000 progressive resolutionencoding may be used for video encoding. For instance, each video framemay be considered a still image and individually encoded using JPEG 2000or a similar encoding technique. In such a case, multiple layers foreach video frame may be compressed, where the layers are ordered frommost significant to least significant (in terms of the amount that eachlayer affects the video image). In this way, any overflow into thecompensation QAM may start with the least significant layers, therebyaffecting the video as little as possible in the event that thecompensation value data is not utilized by the customer. Thus, in thisexample, the compensation values would be or otherwise represent thoselayers that were removed from the JPEG 2000 encoded frames being sentover the content QAM.

Regardless of the type of information lost during this compression, byseparating out the compensation value data identifying the lostinformation, the original MPEG stream may be split between the contentQAM and the compensation QAM such that the content QAM maximum bandwidthis not exceeded. Moreover, because the customer receives both thecontent QAM and the compensation QAM, the customer is able toreconstruct the MPEG stream using the compensation value data back to(or close to) its original information state prior to the lossycompression. In the alternative, the same QAM may contain both contentand compensation value data for that content or for other content.

FIG. 6 is a graph showing illustrative utilized bandwidth over timewithin one of the frequency bands of FIG. 3 used as a compensation QAM,such as QAM-4. In this example, the compensation value data for contentQAM-1, content QAM-2, and content QAM-3, are all transmitted on the samecompensation QAM-4. For each content QAM, the corresponding compensationvalue data may be identified by a unique PID identified in eachcompensation value data packet. As can be seen, the compensation valuedata may be expected to utilize significantly less bandwidth than thecontent to which the compensation value data corresponds. Accordingly,it may be expected that in many instances even a single compensation QAMhaving the same or a smaller maximum available bandwidth than a contentQAM may still be able to accommodate the compensation value data for aplurality of such content QAMs. As can also be seen, at various timesthere are no compensation values at all for a given content QAM. Thesetimes correspond in this example to times when the content in thecorresponding content QAM does not exceed the maximum availablebandwidth for that content QAM.

FIG. 7 is a flowchart of an illustrative process that may be performedby CPE 105 and/or 106 of FIG. 1 to decompress the received compresseddata utilizing received compensation value data. For purposes ofexplanation, it will be assumed that CPE 105 is performing the receivingand decompression. In step 701, CPE 105 uses Tuner A to select thedesired PID of the desired channel. For example, Tuner A may selectchannel 2 in content QAM-1 of FIG. 4.

In step 702, CPE 105 may determine whether Tuner B (or some other tunerof CPE 105) is available. Tuner B may be unavailable for any reason,such as already being tuned to another channel being recorded to adigital video recorder. If Tuner B (or any tuner other than Tuner A) isunavailable, then decompression of the selected PID content may beperformed in a conventional manner in step 703, and the resultingdecompressed content may be rendered in step 704, such as by beingdisplayed on display device 107.

If Tuner B (or any other tuner) is available, then in step 705 Tuner Bselects the PID for the compensation value data that corresponds to thePID of the selected channel (in this example, the compensation valuedata that corresponds to content channel 2). To accomplish this, forexample, CPE 105 may have stored in a computer-readable medium a tableassociating each channel and/or content QAM with a compensation valuePID. An example of such a table is shown below in Table 1, usingarbitrary PID values. Alternatively, there may be a known correspondencebetween content channel PIDs and compensation value PIDs, where thecompensation value PID may be calculated from the content channel PID(such as by adding a constant value to the content channel PID). As yetanother alternative, a low data-rate feed may be included in eachcontent QAM (and thus received by CPE 105) that maps the PID of thecontent for each channel with the PID of the corresponding compensationvalue data. While in the example of Table 1 the PID of a channel isdifferent from the PID of the related compensation value data, it ispossible that the PID may be the same for both. The bandwidth used bythe low data-rate feed may be taken into account when defining theremaining maximum bandwidth capacity of a content QAM available forchannel content.

TABLE 1 Channel PID Compensation Value PID 1 501 2 502 3 503 . . . . . .499 999

Then, in step 706, CPE 105 decompresses the compressed content datareceived by Tuner A using the associated compensation value datareceived by Tuner B, and the resulting decompressed content may berendered in step 704. This process of FIG. 7 may be repeatedcontinuously while content is being received and rendered, and CPE 105may dynamically switch between the 702-703-704 branch of the flowchartand the 702-705-706-704 branch of the flowchart, depending upon theavailability of Tuner B at any given time. Such switching may beautomatic and may be transparent to the user of CPE 105. Of course,where there is no compensation value data for the selected contentchannel, then step 706 may be performed without the benefit of thecompensation value data.

In step 706, the compensation value data may be used in a mannersuitable to the type of compensation values provided and/or the type ofcompression experienced by the content data. For example, where thecompensation values represent lower-significance layers generated usingthe JPEG 2000 technique or a similar technique, then one or more ofthose layers may be represented by the compensation values and may beadded back in to the content data for decompression.

Thus, techniques for providing compensation values of content QAMscontaining content that has been compressed in a lossy manner have beendescribed. While certain embodiments have been described herein, suchembodiments are merely illustrative, and variations are possible whilestill remaining within the scope and spirit of the present disclosure.For example, while content and compression QAMs have been illustrativelydescribed as utilizing quadrature amplitude modulation, any other typeof bandwidth regions with any other type of modulation may be utilizedin place of the QAM bandwidth regions described herein. Moreover, whilethe content QAMs as described herein have a fixed maximum bandwidth,this is not necessary. A content QAM (or other type of bandwidth region)may have a variable maximum bandwidth even though the compensationvalues are provided to the customer outside of that content QAMbandwidth.

1. (canceled)
 2. A method, comprising: transmitting, by at least onetransmitter, a first plurality of data streams each in a respectivefrequency band, the first plurality of data streams each comprising acompressed version of content; and transmitting a second plurality ofdata streams in a frequency band different from the respective frequencyband of each of the first plurality of data streams, each of the secondplurality of data streams comprising data corresponding to informationlost from compression of the content of a respective one of the firstplurality of data streams.
 3. The method of claim 2, further comprisingcompressing, by at least one computing device, the content to generatethe compressed version of the content.
 4. The method of claim 2, furthercomprising compressing, by at least one computing device, at least oneof the first plurality of data streams in response to a determinationthat transmission of data comprising the at least one of the firstplurality of data streams would exceed a predetermined bandwidth.
 5. Themethod of claim 2, wherein the transmitting the second plurality of datastreams is performed at least partially simultaneously with thetransmitting the first plurality of data streams.
 6. The method of claim2, wherein the transmitting the first plurality of data streamscomprises transmitting a first data stream of the first plurality ofdata streams and a second data stream of the first plurality of datastreams, the first data stream having a first program identifier (PID)and the second data stream having a different second PID.
 7. The methodof claim 6, wherein the transmitting the second plurality of datastreams comprises transmitting a third data stream of the secondplurality of data streams and a fourth data stream of the secondplurality of data streams, the third data stream having a third PID andthe fourth data stream having a fourth PID, wherein the first PID, thesecond PID, the third PID, and the fourth PID are all different.
 8. Themethod of claim 7, further comprising determining the third PID based atleast in part on the first PID.
 9. The method of claim 7, furthercomprising determining the third PID by combining the first PID with afixed value.
 10. The method of claim 2, wherein the transmitting thefirst plurality of data streams and the transmitting the secondplurality of data streams are performed by a plurality of transmitterscomprising the at least one transmitter.
 11. A method, comprising:receiving, by a computing device: a first plurality of data streams eachin a respective frequency band, the first plurality of data streamscomprising a compressed version of content; and a second plurality ofdata streams in a frequency band different from the respective frequencyband of each of the first plurality of data streams, the secondplurality of data streams comprising data corresponding to informationlost from a compression of the content; and generating, by the computingdevice, a signal for display using at least one data stream of the firstplurality of data streams and at least one data stream of the secondplurality of data streams.
 12. The method of claim 11, furthercomprising sending the signal to a display device.
 13. The method ofclaim 11, wherein the generating the signal for display comprisesmodifying the at least one data stream of the first plurality of datastreams using the at least one data stream of the second plurality ofdata streams.
 14. The method of claim 11, wherein the receiving thefirst plurality of data streams comprises receiving a first data streamof the first plurality of data streams and a second data stream of thefirst plurality of data streams, the first data stream having a firstprogram identifier (PID) and the second data stream having a differentsecond PID.
 15. The method of claim 14, wherein the receiving the secondplurality of data streams comprises receiving a third data stream of thesecond plurality of data streams and a fourth data stream of the secondplurality of data streams, the third data stream having a third PID andthe fourth data stream having a fourth PID, wherein the first PID, thesecond PID, the third PID, and the fourth PID are all different.
 16. Themethod of claim 15, further comprising: selecting the first PID to tunethe computing device to the first data stream; determining the third PIDbased at least in part on the first PID; and selecting the third PID totune the computing device to the third PID, wherein the generating thesignal for display comprises generating the signal for display using thefirst data stream and the third data stream.
 17. The method of claim 15,further comprising: selecting the first PID to tune the computing deviceto the first data stream; determining the third PID by combining thefirst PID with a fixed value; and selecting the third PID to tune thecomputing device to the third PID, wherein the generating the signal fordisplay comprises generating the signal for display using the first datastream and the third data stream.
 18. A method, comprising:transmitting, by at least one transmitter, a first plurality of datastreams each in a respective frequency band, the first plurality of datastreams each comprising content of a first quality; and transmitting asecond plurality of data streams in a frequency band different from therespective frequency band of each of the first plurality of datastreams, each of the second plurality of data streams comprising datathat, in combination with a respective one of the first plurality ofdata streams, represents content of a second quality higher than thefirst quality.
 19. The method of claim 18, wherein the first qualitycomprises a first resolution and the second quality comprises a secondhigher resolution.
 20. The method of claim 18, wherein the transmittingthe second plurality of data streams is performed at least partiallysimultaneously with the transmitting the first plurality of datastreams.
 21. The method of claim 18, further comprising generating, forat least one of the first plurality of data streams, the content of thefirst quality by using compression.